Noob Light Bar Wiring Question

All the harnesses I'm looking at come with a pre wired relay that goes to the light bar itself as well as an on/off switch. Every one of them shows to wire the positive directly to the battery.

My question/concern is: By doing so, won't both the "on" and "off" lights on the on/off switch itself always be on since power is directly to the battery even if the truck is off?

 

Yeah, that setup would be always on if the switch is on. If you wanted to make it ignition controlled, you could tap a 12v feed using an add-a-fuse in an open spot on your interior fuse panel, feeding your supply line to the switch. The relay power would still come off the battery, the trigger from the switch would just be fed via ignition power.

 

That makes sense.

Kind of weird all these diagrams say to go direct to the battery. I'm sure there's minimal draw for the light on the switch, but eventually it would kill the battery I would imagine.

 

If I wanted to be super lazy, couldn't I simply (and more importantly, safely) simply disconnect the ground from the switch itself? It will (safely) still work but just not light up, won't it? Or will it still draw power even though it won't light up?

 

Bump for my previous noob question.

 

Show me/us an example of the wiring schematics you're referencing here, and we'll provide more accurate answers.

Anyway,
In a standard/simple relay wiring schematic 12V+ is supplied from the battery to the relay. This "sits there, unused" until the relay is "told to" let the juice flow. To make that happen you connect a switch to one of the terminal on that relay, and then provide a 12V+ power on the other side of the switch. So now we have power going to the switch as well....unused (circuit is open) until you flip that switch. Power for the switch can come straight from battery itself (this way you can activate the switch no matter if the car is on/off/accessory/etc). If you provided 12V+ to your switch from an accessory ON source (cigarette lighter wire tap is a good example) then your switch will only work once that accessory is ON (truck on, keys in, etc).
In either case - switches which have a built-in LED indicator light (to let you know the switch is ON) are usually wired so that the light comes on only after the switch is turned on.

In other terms: you're not using battery/draining power unless a circuit is closed, and something is actively drawing current (light/etc), thus having 12V+ from battery connected to relay, switch or just a wire to hold in your hand does nothing. Your entire truck has 12V+ running to 100s of things continuously, and they all start working (draining power source) after you flip a switch (open a door, turn a key, flip a switch, ECU tells something to provide 12V+, etc).

If all you mean is to have the switch indicator light disconnected (if it lights up when you turn it on), then yes, you can do that, and the switch will work as before but you just won't have a light on it. It all depends on thee switch however, and how it's wired up.
Some have all wiring, some are 'bonded internally'/etc. If you disconnect the ground wire for the indicator light itself, then that light won't work anymore, but the switch will as usual.


Hope these [perhaps] over-simplified answers gives you a better understanding of this. May seem a bit confusing but it's all fairly simple; wiring examples of switches/etc would prob give you a good visual.

There are many ways to wire things up, so this is only a basic example.
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